Sunday, February 14, 2016
Thursday, February 11, 2016
Astronomical Spectroscopy for Amateurs. It is well written but looks quite daunting when you first pick it up. However if you work through it bit by bit, its a great book with everything you need to know. Feeling a little more confident, I invested in the next logical step - a Star Analyser 100. This is the entry level standard for beginners, and produces fine results as we'll see. After passing it around the family to have a look at the cool effects looking at the ceiling lights, I lost the plot and departed from Ken's careful, meticulously presented steps, with the outrageous thought - I wonder how this baby would go on an iPhone! I am constantly amazing at STEM events and star parties how the "younglings" immediately are so amazed by what they see through the eyepiece they want to whip out the smartphone and take an image home with them. Surely it couldn't possibly work. After all the iPhone 6 sensor is only 4.8mm by 3.6mm, it has a focal length of 29mm and is f2.2. But its an 8M pixel camera (said my evil twin subconscious), your Fingerlakes PL11000M is only 11M pixels so its only 3000 less pixels, how bad could it be....hang-on whats the pixel size ...ah 1.5um versus 9um, interesting. So the sensor is 3264 x 2448, interesting ..... iPhones do take good photos......on a sunny day.....not in the night sky. This went on for a while! So in the end there was nothing else to do but try it, and learn from your spectacular mistakes! 645 Pro could even do it with an Kodak Ektrachrome 64 film "feel to it". NOTE: to those born after the 90's, can you imagine only getting 36 images on one roll of film and not being able "to delete the bad ones" until after you had paid $25 and sent it off to the developers and had it returned to your letter box. In those days the lens ONLY pointed away from you - THE HORROR! Anyway I digress. 645 Pro basically turns your iPhone into a simulated DSLR and enters the workflow of the photography before any JPEG compression. You can set ISO and shutter speed, bracket exposures do all sorts of things that you can do on a DSLR. With my trusty new app, my camera adapter, my star analyser, a 25mm eyepiece, I was ready for action.
Friday, February 5, 2016
In my continuing efforts to de-mystify the art of Asteroid Astrometry, I thought I'd follow up last week's article on about 2016 BE with a deeper examination of the Uncertainty parameter when its listed in orbital elements. This week there is some attention on 2013 TX68 which will possibly make a record close pass of 11,000 klms or possibly be 40 times further away than the moon on March the 5th. I can see that puzzled look on your face ;-) 2013 TX68 is also a Virtual Impactor in 2017, a term we discussed last week. So firstly lets get some perspective on this uncertainty thing. 2011 CF66 was also listed as a virtual impactor for Feb 2nd 2016, it didn't hit us, no-one was worried if it would, and in fact no-one has any idea where it actually is. It is only a tiny asteroid about 3-9m in diameter and wouldn't have done any damage even if it did. In fact there are 20 other virtual impactors listed in the Risk Table this year, the next one might approach on Feb 18th, is 2009 VZ39, and is slightly smaller than 2013 TX68. 2009 VZ39 is also in the daytime sky and not observable for follow up and further confirmation. I only highlight this to emphasise the point here - all asteroids once they are discovered need to be tracked for sometime, to improve the precision of the orbit before any pronouncements about where they are going to be at a certain point in time. The difference between 2013 TX68 and 2009 VZ39 for example is that 2013 TX68 was observed for 31 data positions (astrometry) over 3 nights where as 2009 VZ39 was observed on only one night with 8 astrometric data positions. If you look at the orbital elements for 2013 TX68 the uncertainty parameter is listed as 7, where as for 2009 VZ39 there is not even enough data to start that calculation. For 2011 CF66, there is a 1.1e-8 chance of a collision between 2016 and 2114, so its mathematically possible, but highly unlikely. NASA/JPL produced this nice graph with it's press release this week which illustrates the point well.
Friday, January 29, 2016
Sentry Risk Table is for the 3rd February 2053 .... NOT ON THIS PASS!!!! As you would expect the "zone of uncertainty" for 2053 is much large than the "zone of uncertainty" for next week. So it will take many further observations before it is (most likely) removed from the risk table. Its current risk table score of Torino-0 just means that at this point the chance of a collision in 2053 has not been able to be eliminated at this stage. Measured position: K16B00E KC2016 01 28.46044 12 04 01.15 +65 50 49.0 16.9 R H06 K16B00E KC2016 01 28.46319 12 04 09.44 +65 49 54.8 17.3 R H06 K16B00E KC2016 01 28.46604 12 04 18.01 +65 48 58.7 17.4 R H06
Wednesday, December 9, 2015
Victorian Space Science Education Centre and Telescopes in Schools program who hosted me yesterday running a variable star workshop with students and science teachers. The staff were magnificent and the centre is a real credit to all involved. iTelescope.net's Telescopes. Planet Hunter target from the Kepler Mission that exhibited some strange and difficult to explain behaviours.
Thursday, October 15, 2015
UPDATE: Oct 31st, 2015. Live coverage of Asteroid 2015 TB145. see the post on the SETI Institute Blog. Also from the press realease: "NASA values the work of numerous highly skilled amateur astronomers, whose accurate observational data helps improve asteroid orbits....". I hope to have more images tonight (weather permitting) - stay tuned. After last week's blog post about the Blogsphere overeacting to an Asteroid that astronomers knew about for 15 years passing at 65 Lunar Distances (LD), the "surprise" of course had to happen this week. This will be an interesting two weeks, as Asteroid 2015 TB145 will cruise by Earth just outside 1 Lunar distance (1.3 LD). The asteroid is a target of the Arecibo Observatory (that big antenna that rose out of the lake in the majestic James Bond scene), and to get some really great radar tracking and detailed images, the ephemeris and position of the asteroid needs very high precision. To give you an idea of the type of imaging to be obtained (see below), a similar situation occured last year for 2014 HQ124. These were some of the best radar images ever recorded, and some of my data was used to refine the orbit for targeting on that occasion. Image Credit: Asteroid 2014 HQ124 Radar images from Goldstone - NASA/JPL This asteroid is twice as big (between 290 and 650 meters diameter - most astronomers are calling it about 480m) and twice as close as 2014 HQ124, so you can only imagine how good the images should be. Professional Observatories and amateur astronomers will be tracking it closely to improve the precision of the orbit as it approaches. I was quite chuffed when tracking 2014 HQ124 that my light curve had a few bumps in it and I made the call it was "not round" which was subsequently confirmed by the radar images. So who knows what the next two weeks will turn up? What we know at this stage is that is going to be quite bright and could be visible in binoculars. Also its speed is very fast, but its moving slowly across the images at the moment as you can see, because of the angle its approaching us at. As it makes its close approach its going to do a nice "flyby" of the Crab Nebula M1 for Northern Hemisphere viewers on Oct 29th/30th Ian Musgrave has details on his blog shortly. So stay tuned, I'll be following it closely and providing some regular updates.